textproduct: Rapid City

KEY MESSAGES

- Cool and breezy unsettled weather expected Thursday through the weekend.

UPDATE

Issued at 727 PM MDT Wed Apr 22 2026

01z surface analysis had robust low over the MT/ND/Canadian border with a warm front into IL and an impressive dry-line/trough into western NE. It has been the focus for high-based convection this evening per 0.5-1KJ/kg MLCAPE and 1500J/kg DCAPE. Result has been a mix of convective/non-convective wind reports, with the highest focus on outflow boundaries where severe thunderstorm warnings were issued. Expect additional convection this evening over south- central SD per CAMS/dry-line/trough interaction. Further west over the higher terrain, deep boundary layer mixing resulting in frequent wind gusts around 45kts with a few locally higher reports. The last few hours of the 0.5km visible satellite imagery has been interesting with terrain effects. HRRR has been persistent in an uptick in winds over the Black Hills this evening, so will keep an eye on them. Forecast has been updated to account for these features.

Looking ahead to Thursday, latest guidance suggests a period of high winds over northwestern SD per gradient/daytime mixing. Latest NBM guidance gives 50-80% chance of 50kt gusts for K2WX- KRCA. Left Rapid City out given the significant westerly component to the wind direction. Hoisted a Wind Advisory just to the east of the warning and also put one out for far southwestern SD per current/expected wind gusts this evening and then Thursday. Some rain/snow showers will wrap into northeastern WY/northwestern SD by Thursday morning as parent upper low spins into ND with backwash moisture.

Jury is still out on stripe of potential QPF/snow Thursday night and Friday as another shortwave rotates around the upper low so will continue with highest PoPs across the southwestern half of the CWA.

Finally, will let the Red Flag Warning expire at 8pm. Conditions will very slowly improve tonight.

DISCUSSION

(This Evening Through Wednesday) Issued at 101 PM MDT Wed Apr 22 2026

Plenty of weather to talk about today that's for sure. For starters, a quick look at the calendar is a good way to remind yourself that it's not June or July but April! Afternoon temps have soared well beyond the normal for late April and have reached the 80s and 90s, which is near 25 to 30 degrees above normal. Strong southerly winds, with gusts upwards of 40 to 50 mph, have helped to usher in that warmer air. To add to this, very low humidities, down to near 10%, means we are seeing critical fire weather conditions around the area. These conditions will last through the early evening. Then temps will cool, humidity will recover, and winds will relax.

The next part of the forecast we are focusing on is the potential for strong to severe thunderstorms later this afternoon and evening. A boundary is tracking through the upper plains and strong to severe storms are possible along that boundary. The main concern for the mode of severe weather is wind gusts. The area of concern for where the storms could pop up is pretty much the all of western SD but higher confidence in the central part of the state, so stay plugged into the weather through the evening for the latest.

Late tonight and Thursday brings a passing cold front, that will swing winds to the west and increase them, again, to gusts upwards of 40 to 50 mph. These westerly winds will usher in cooler air, so expect daily highs to drop to the 40s and 50s. Overnight lows will dip into the 20s to low 30s. Temps like this are below normal for this time of year.

Friday and beyond, the northwest flow will keep an active pattern in place so we are looking at on/off rain or showers to linger in the forecast. And with cold temps at night, any precip we see could fall as a rain/snow mix, or all snow, during the cold times of the day. The higher elevations of the Black Hills have a high chance of seeing accumulating snow Saturday night. Stay plugged into the forecast over the coming days for the details.

AVIATION

(For the 12Z TAFS Through 12Z Friday Morning) Issued At 528 AM MDT Thu Apr 23 2026

A cold front will move through the region with gusty west/northwest winds behind it as well as some -shrasn and areas MVFR/local IFR conditions across northeastern WY/northwestern SD. Wind gusts over 50 knots will be possible across NW SD. Another disturbance will bring a chance of rain/snow to the SW half tonight, with more MVFR (local IFR) conds.

UNR WATCHES/WARNINGS/ADVISORIES

SD...High Wind Warning from 9 AM this morning to 6 PM MDT this evening for SDZ001-002-012-013-031-072-073-078. Wind Advisory from 9 AM this morning to 6 PM MDT this evening for SDZ014-032. Wind Advisory until 6 PM MDT this evening for SDZ027-041-075. WY...None.